The purpose of this project is to define the regions of the brain, the neuronal pathways, and the neurotransmitter systems which control endocrine, metabolic and autonomic responses to internal systems which control endocrine, metabolic and autonomic responses to internal stimulic and to various types of stress and the effects of drugs on these systems. Studies on intracerebral injections of prostaglandin F2Alpha and opiates were completed. Changes in dopamine receptors were examined in relation to the role of prolactin in producing supersensitivity of dopamine receptors. Vasopressin mediation of baroreflexes in the brain and its role in sustaining blood pressure responses to baroreceptor deafferentation were examined.